The benefits of calcium

Some studies suggest that calcium, along with vitamin D, may have benefits beyond bone health, perhaps protecting against cancer, diabetes and high blood pressure. But evidence about such health benefits is not definitive.

The risks of too little calcium

If you don't get enough calcium, you could face health problems related to weak bones:

Children may not reach their full potential adult height.

Adults may have low bone mass, which is a risk factor for osteoporosis.

Many Americans don't get enough calcium in their diets. Children and adolescent girls are at particular risk, but so are adults age 50 and older.

Calcium requirements

How much calcium you need depends on your age and sex. Note that the upper limit in the chart represents the safe boundary — it's not how much you should aim to get. If you exceed the upper limit, you may increase your risk of health problems related to excessive calcium.

Calcium: Recommended Dietary Allowance (RDA) for adults

Men

Daily RDA

Daily upper limit

19-50 years

1,000 mg

2,500 mg

51-70 years

1,000 mg

2,000 mg

71 and older

1,200 mg

2,000 mg

Women

19-50 years

1,000 mg

2,500 mg

51 and older

1,200 mg

2,000 mg

Calcium and vitamin D

Your body needs vitamin D to absorb calcium. For this reason, some calcium supplements contain vitamin D. A few foods naturally contain small amounts of vitamin D, such as canned salmon with bones, and egg yolks. You can also get vitamin D from fortified foods and sun exposure. The RDA for vitamin D is 600 international units (15 micrograms) a day for most adults.

Calcium and diet

Your body doesn't produce calcium, so you must get it through other sources. Calcium can be found in a variety of foods, including:

Dairy products, such as cheese, milk and yogurt

Dark green leafy vegetables, such as broccoli and kale

Fish with edible soft bones, such as sardines and canned salmon

Calcium-fortified foods and beverages, such as soy products, cereal and fruit juices

Even if you eat a healthy, balanced diet, you may find it difficult to get enough calcium if you:

Follow a vegan diet

Have lactose intolerance and limit dairy products

Consume large amounts of protein or sodium, which can cause your body to excrete calcium

Have osteoporosis

Are receiving long-term treatment with corticosteroids

Have certain bowel or digestive diseases that decrease your ability to absorb calcium, such as inflammatory bowel disease or celiac disease

In these situations, calcium supplements may help you meet your calcium requirements.

Types of calcium supplements

Several different kinds of calcium compounds are used in calcium supplements. Each compound contains varying amounts of the mineral calcium — referred to as elemental calcium. Common calcium supplements may be labeled as:

Calcium carbonate (40 percent elemental calcium)

Calcium citrate (21 percent elemental calcium)

Calcium gluconate (9 percent elemental calcium)

Calcium lactate (13 percent elemental calcium)

The two main forms of calcium supplements are carbonate and citrate. Calcium carbonate is cheapest and therefore often a good first choice. Other forms of calcium in supplements include gluconate and lactate.